stats study sets 1.1-2.2

CHAPTER 1

CHAPTER 1

The following data were collected from a random sample of people on their favorite types of leisure activities and their age. The results are shown in the two-way table below. What proportion of the people aged 7 to 18 years gave watching television as their favorite type of leisure activity? A 300/2,200 B 200/900 C 100/1,300 D 640/3,500 E 300/640

A 300/2,200

The histogram above shows the number of minutes needed by 45 students to finish playing a computer game. Which of the following statements is correct? A The distribution is skewed to the right. B The distribution is skewed to the left. C The distribution appears to be normal. D The distribution appears to be chi-square. E The distribution appears to be uniform.

B The distribution is skewed to the left.

One statistic calculated for pitchers in baseball is called the earned run average, or ERA. The following boxplots summarize the ERA for pitchers in two leagues, A and B. Based on the boxplots, which of the following statistics is the same for both leagues? A The range B The interquartile range C The median D The minimum E The maximum

B The interquartile range

Each value in a sample has been transformed by multiplying by 3 and then adding 10. If the original sample had a variance of 4, what is the variance of the transformed sample? A 4 B 12 C 16 D 22 E 36

E 36

A statistician at a metal manufacturing plant is sampling the thickness of metal plates. If an outlier occurs within a particular sample, the statistician must check the configuration of the machine. The distribution of metal thickness has mean 23.5 millimeters (mm) and standard deviation 1.4 mm. Based on the two-standard deviations rule for outliers, of the following, which is the greatest thickness that would require the statistician to check the configuration of the machine? A 19.3mm B 20.6mm C 22.1mm D 23.5mm E 24.9mm

B 20.6mm

The boxplots above summarize two data sets, A and B. Which of the following must be true? Set A contains more data than Set B. The box of Set A contains more data than the box of Set B. The data in Set A have a larger range than the data in Set B. A I only B III only C I and II only D II and III only E I, II, and III

B III only

New employees at a large corporation go through a training program during their first week of employment. The new employees take a written assessment at the completion of the program to determine how well prepared they are for their jobs. A score greater than the mean indicates a well-prepared employee. Assume the following distributions of new employee scores have the same mean score, the same maximum score, and the same minimum score. Which distribution has a shape that is most likely to represent the greatest percent of well-prepared employees? A The distribution of scores is skewed to the right. B The distribution of scores is skewed to the left. C The distribution of scores is bimodal and symmetric. D The distribution of scores is uniform. E The distribution of scores is approximately normal.

B The distribution of scores is skewed to the left.

A school is having a contest in which students guess the number of candies in a jar. The student whose guess is closest to the correct number of candies in the jar wins a prize. The number of candies guessed by male and female students is shown in the back-to-back stemplot below. Which of the following statements is true about the distributions of guesses? A The distribution of guesses for male students is skewed to the left, and the distribution of guesses for female students is skewed to the right. B The distribution of guesses for male students is skewed to the right, and the distribution of guesses for female students is skewed to the left. C The distributions of guesses for male and female students are both skewed to the right. D The distributions of guesses for male and female students are both skewed to the left. E The distributions of guesses for male and female students are both symmetric.

D The distributions of guesses for male and female students are both skewed to the left.

The histogram shows the distribution of heights, in inches, of 100 adult men. Based on the histogram, which of the following is closest to the interquartile range, in inches, of the distribution? A 2 B 5 C 9 D 12 E 15

B 5

The following list shows the number of video games sold at a game store each day for one week. 15, 43, 50, 39, 22, 16, 20 Which of the following is the best classification of the data in the list? A Categorical and continuous B Quantitative and continuous C Categorical and discrete D Quantitative and discrete E Neither categorical nor quantitative, and neither discrete nor continuous

D Quantitative and discrete

A graduate student conducted a study of field mice in rural Kansas. The student obtained a sample of 100 field mice and recorded the weight, in grams, of each mouse. After the measurements were taken, it was discovered that the scale was not calibrated correctly. The student adjusted the 100 recorded measurements by subtracting 3 grams from each measurement. Which of the following statistics for the weight, in grams, of the field mice has the same value before and after the adjustment? A The median B The mean C The first quartile D The third quartile E The interquartile range

E The interquartile range

The weight of adult male grizzly bears living in the wild in the continental United States is approximately normally distributed with a mean of 500 pounds and a standard deviation of 50 pounds. The weight of adult female grizzly bears is approximately normally distributed with a mean of 300 pounds and a standard deviation of 40 pounds. Approximately, what would be the weight of a female grizzly bear with the same standardized score (z-score) as a male grizzly bear with a weight of 530 pounds? A 276 pounds B 324 pounds C 330 pounds D 340 pounds E 530 pounds

B 324 pounds

First-year students enrolled at a college were asked whether they play video games. The responses, classified by whether the students were enrolled in the school of sciences or the school of arts, are shown in the table. Of all the students enrolled in the school of arts who responded, approximately what proportion responded that they play video games? A 0.242 B 0.401 C 0.438 D 0.554 E 0.605

C 0.438

A group of students played a game in which they earned points for answering questions correctly. The following dotplot shows the total number of points earned by each student. Which of the following is the best description of the distribution of points earned? A Approximately normal B Bimodal without a gap C Bimodal with a gap D Skewed to the right without a gap E Skewed to the right with a gap

C Bimodal with a gap

A random sample of 25 households from the Mountainview School District was surveyed. In this survey, data were collected on the age of the youngest child living in each household. The histogram below displays the data collected in the survey. In which of the following intervals is the median of these data located? A 0 years old to less than 2 years old B 4 years old to less than 6 years old C 6 years old to less than 8 years old D 8 years old to less than 10 years old E 10 years old to less than 12 years old

D 8 years old to less than 10 years old

The following boxplot summarizes the heights of a sample of 100 trees growing on a tree farm. Emily claims that a tree height of 43 inches is an outlier for the distribution. Based on the 1.5×IQRrule for outliers, is there evidence to support the claim? A Yes, because (max−Q3) is greater than (Q1−min). B Yes, because 43 is greater than (Q3+IQR). C Yes, because 43 is greater than (Q1−1.5×IQR). D No, because 43 is not greater than (Q3+1.5×IQR). E No, because 43 is greater than (Q1−1.5×IQR).

D No, because 43 is not greater than (Q3+1.5×IQR).

A distribution of test scores is not symmetric. Which of the following is the best estimate of the z-score of the third quartile? A 0.67 B 0.75 C 1.00 D 1.41 E This z-score cannot be estimated from the information given.

E This z-score cannot be estimated from the information given.

The following frequency table shows the responses from a group of college students who were asked to choose their favorite flavor of ice cream. Which of the following statements is not supported by the table? A The number of student responses is 300. B One-third of the students chose vanilla. C One-third of the students chose chocolate or strawberry. D One-fourth of the students chose mint chip or coffee. E One-half of the students chose vanilla or chocolate.

E One-half of the students chose vanilla or chocolate.

Roger claims that the two statistics most likely to change greatly when an outlier is added to a small data set are the mean and the median. Is Roger's claim correct? A Yes, both the mean and median are likely to change greatly. B No, only the mean is likely to change greatly. C No, only the median is likely to change greatly. D No, neither the mean nor the median are likely to change greatly. E There is not enough information to determine if the mean or the median is likely to change greatly.

B No, only the mean is likely to change greatly.

A veterinarian collected data on the weights of 1,000 cats and dogs treated at a veterinary clinic. The weight of each animal was classified as either healthy, underweight, or overweight. The data are summarized in the table. Based on the data in the table, which of the following is the most appropriate type of graph to visually show whether a relationship exists between the type of animal and the weight classification? A Back-to-back stemplots B Scatterplot C Side-by-side boxplots D Segmented bar chart E Dotplot

D Segmented bar chart

A sample of 100 students from Liberty High School and a sample of 60 students from Central High School were asked what they planned to do after graduation. Responses fell into five categories: four-year university (4Y), community college (CC), join the workforce (W), join the military (M), or undecided (UD). The results are shown in the following bar chart. Which of the following statements is supported by the bar chart? A For the category four-year university, the number of students from Central High School was 10 greater than the number of students from Liberty High School. B At Liberty High School, more students selected a four-year university than any other activity. C For the category join the workforce, the number of students from each school was equal. D At Central High School, the same number of students selected four-year university and military. E For the category undecided, the number of students from Liberty High School was 4 greater than the number of students from Central High School.

E For the category undecided, the number of students from Liberty High School was 4 greater than the number of students from Central High School.

A child psychologist asked 100 five year olds and 50 ten year olds to name their favorite color. Their results are shown in the following table. Which of the following statements is supported by the table? A The percentage of five year olds who selected red or blue as their favorite color is greater than the percentage of ten year olds who selected red or blue as their favorite color. B The percentage of five year olds who selected yellow as their favorite color is greater than the percentage of ten year olds who selected yellow as their favorite color. C The percentage of children who selected red, yellow, or blue as their favorite color was equal for both ages. D Less than half of the five year olds selected red, yellow, or blue as their favorite color. E Less than half of the ten year olds selected red, yellow, or blue as their favorite color.

A The percentage of five year olds who selected red or blue as their favorite color is greater than the percentage of ten year olds who selected red or blue as their favorite color.

A candy company produces individually wrapped candies. The quality control manager for the company believes that the weight of the candies is approximately normally distributed with mean 720 milligrams (mg).If the manager's belief is correct, which of the following intervals of weights will contain the largest proportion of the candies in the distribution of weights? A 740 mg to 780 mg B 700 mg to 740 mg C 680 mg to 720 mg D 660 mg to 700 mg E 620 mg to 660 mg

B 700 mg to 740 mg

Scientists estimate that the distribution of the life span of the Galápagos Islands giant tortoise is approximately normal with mean 100 years and standard deviation 15 years. Based on the estimate, which of the following is closest to the age of a Galápagos Islands giant tortoise at the 90th percentile of the distribution? A 80 years B 115 years C 120 years D 125 years E 130 years

C 120 years

A random sample of 374 United States pennies was collected, and the age of each penny was determined. According to the boxplot below, what is the approximate interquartile range (IQR) of the ages? A 8 B 10 C 16 D 40 E 50

C 16

Of the following dotplots, which represents the set of data that has the greatest standard deviation? A B C D E

B

A data set of test scores is being transformed by applying the following rule to each of the raw scores. Transformed score = 3.5(raw score) + 6.2 Which of the following is NOT true? A The mean transformed score equals 3.5(the mean raw score) + 6.2. B The median transformed score equals 3.5(the median raw score) + 6.2. C The range of the transformed scores equals 3.5(the range of the raw scores) + 6.2. D The standard deviation of the transformed scores equals 3.5(the standard deviation of the raw scores). E The IQR of the transformed scores equals 3.5(the IQR of the raw scores).

C The range of the transformed scores equals 3.5(the range of the raw scores) + 6.2.

The following boxplot shows the typical gas mileage, in miles per gallon, for 20 different car models. Based on the boxplot, the top 25 percent of the cars have a typical gas mileage of at least how many miles per gallon? A 15 B 20 C 25 D 35 E 50

D 35

The distribution of the number of transactions per day at a certain automated teller machine (ATM) is approximately normal with a mean of 80 transactions and a standard deviation of 10 transactions. Which of the following represents the parameters of the distribution? A x¯=80;s=10 B x¯=80;s2=10 C x¯=80;σ=10 D μ=80;σ=10 E μ=80;s=10

D μ=80;σ=10

The caffeine content of 8-ounce cans of a certain cola drink is approximately normally distributed with mean 33 milligrams (mg). A randomly selected 8-ounce can containing 35 mg of caffeine is 1.2 standard deviations above the mean. Approximately what percent of 8-ounce cans of the cola have a caffeine content greater than 35 mg? A 1% B 8% C 12% D 16% E 99%

C 12%

Which of the following statements is true about a distribution that appears to have a gap when displayed as a histogram? A The distribution must have an outlier. B The distribution has a region between two data values where no data were observed. C The distribution is approximately normal. D The distribution cannot be symmetric. E The distribution must be bimodal.

B The distribution has a region between two data values where no data were observed.

A random sample of 1,092 people were asked whether color was a consideration in buying a new car. They were also asked to identify one additional feature that was important. The responses are shown in the table. Which of the following is closest to the proportion of people who responded no to color consideration and who identified safety as the additional feature that was important? A 0.18 B 0.34 C 0.36 D 0.49 E 0.51

A 0.18

A sleep time of 15.9 hours per day for a newborn baby is at the 10th percentile of the distribution of sleep times for all newborn babies. Assuming the distribution is normal with standard deviation 0.5 hour, approximately what is the mean sleep time, in hours per day, for newborn babies? A 15.1 B 15.3 C 16.3 D 16.5 E 16.7

D 16.5

A company determines the mean and standard deviation of the number of sick days taken by its employees in one year. Which of the following is the best description of the standard deviation? A Approximately the mean distance between the number of sick days taken by individual employees and the mean number of sick days taken by all employees B Approximately the median distance between the number of sick days taken by individual employees and the median number of sick days taken by all employees C The distance between the greatest number of sick days taken by an employee and the mean number of sick days taken by all employees D The number of days separating the fewest sick days taken and the most sick days taken when considering all employees E The number of days separating the fewest sick days taken and the most sick days taken when considering the middle 50 percent of the distribution

A Approximately the mean distance between the number of sick days taken by individual employees and the mean number of sick days taken by all employees

Data were collected on the amount, in dollars, that individual customers spent on dinner in an Italian restaurant. The quartiles for these data are given below. Which of the following statements must be true for these customers? A At least half of the customers spent less than or equal to $44.27 and at least half spent greater than or equal to $44.27. B Seventy-five percent of the customers spent between $36.27 and $58.97. C Twenty-five percent of the customers spent less than or equal to $58.97 and the remaining 75 percent spent greater than or equal to $58.97. D The mean amount spent by customers is $44.27. E A majority of customers spent $44.27.

A At least half of the customers spent less than or equal to $44.27 and at least half spent greater than or equal to $44.27.

The following table shows the data collected from students in grades 3 and 4 in an elementary school about their favorite types of pets. Which of the following statements is supported by the table? A Dogs were the type of pet chosen most often by the students at the elementary school. B There were more students surveyed in grade 3 than in grade 4. C The percentage of students who chose cats as their favorite pet was 60%. D The percentage of students in grade 3 who chose dogs as their favorite pet was 55%. E Birds were the type of pet chosen least often by the students in grade 4.

A Dogs were the type of pet chosen most often by the students at the elementary school.

A local real estate magazine used the median instead of the mean when it reported the SAT score of the average student who attends Groveland High School. A graphical display of SAT scores of students who attend Groveland High School indicated that the data were strongly skewed to the right. Which of the following explains why, in this situation, the median is a more accurate indicator of the SAT score of the average student than the mean is? A The mean is affected by the skewness, whereas the median is not. B The median is always the preferred statistic. C The mean will be less than the median when the data are strongly skewed to the right. D The mean should be used only when data are strongly skewed to the left. E The median is equal to one-half the sum of the maximum and minimum SAT scores at Groveland High.

A The mean is affected by the skewness, whereas the median is not.

In northwest Pennsylvania, a zoologist recorded the ages, in months, of 55 bears and whether each bear was male or female. The data are shown in the back-to-back stemplot below. Based on the stemplot, which of the following statements is true? A The median age and the range of ages are both greater for female bears than for male bears. B The median age and the range of ages are both less for female bears than for male bears. C The median age is the same for female bears and male bears, and the range of ages is the same for female bears and male bears. D The median age is less for female bears than for male bears, and the range of ages is greater for female bears than for male bears. E The median age is greater for female bears than for male bears, and the range of ages is less for female bears than for male bears.

A The median age and the range of ages are both greater for female bears than for male bears.

At a photography contest, entries are scored on a scale from 1 to 100. At a recent contest with 1,000 entries, a score of 68 was at the 77th percentile of the distribution of all the scores. Which of the following is the best description of the 77th percentile of the distribution? A There were 770 entries with a score less than or equal to 68. B There were at least 230 entries with a score of 77. C There were 23% of the entries with a score less than or equal to 68. D There were 77% of the entries with a score equal to 68. E There were at least 77% of the entries with a score greater than 68.

A There were 770 entries with a score less than or equal to 68.

The histogram below displays the frequencies of waiting times, in minutes, for 175 patients in a dentist's office. Which of the following could be the median of the waiting times, in minutes? A 2.50 B 7.25 C 12.25 D 15.00 E 17.50

B 7.25

In a standard golf tournament, golfers play 18 holes of golf on each of 4 consecutive days. For each hole, golfers keep track of the number of times they hit the ball (strokes) before the ball goes into the cup. A golfer's score for the tournament is the total number of strokes needed to complete the tournament. The boxplots below summarize the scores for golfers who competed in tournament 1 and golfers who competed in tournament 2. Based on the boxplots, which of the following statements must be true? A More golfers played in tournament 1 than in tournament 2. B In both tournaments, at least half the golfers completed the tournament with a score less than 288. C The number of golfers who completed tournament 1 with a score less than 288 was greater than the number of golfers who completed tournament 2 with a score less than 288. D The range of scores for tournament 1 is less than the range of scores for tournament 2. E The score of the golfer with the least score in tournament 1 was greater than the score of the golfer with the least score in tournament 2.

B In both tournaments, at least half the golfers completed the tournament with a score less than 288.

A company wanted to determine the health care costs of its employees. A sample of 25 employees were interviewed and their medical expenses for the previous year were determined. Later the company discovered that the highest medical expense in the sample was mistakenly recorded as 10 times the actual amount. However, after correcting the error, the corrected amount was still greater than or equal to any other medical expense in the sample. Which of the following sample statistics must have remained the same after the correction was made? A Mean B Median C Mode D Range E Variance

B Median

Resting heart rates, in beats per minute, were recorded for two samples of people. One sample was from people in the age-group of 20 years to 30 years, and the other sample was from people in the age-group of 40 years to 50 years. The five-number summaries are shown in the table. The values 60, 62, and 84 were common to both samples. The three values are identified as outliers with respect to the age-group 20 years to 30 years because they are either 1.5 times the interquartile range (IQR) greater than the upper quartile or 1.5 times the IQR less than the lower quartile. Using the same method for identifying outliers, which of the three values are identified as outliers for the age-group 40 years to 50 years? A None of the three values is identified as an outlier. B Only 60 is identified as an outlier. C Only 60 and 62 are identified as outliers. D Only 60 and 84 are identified as outliers. E The three values are all identified as outliers.

B Only 60 is identified as an outlier.

The prices, in thousands of dollars, of the 35 used cars at a certain car dealership are shown in the table below. Which of the following best describes the shape of the distribution of used car prices at the dealership? A Skewed to the left (negatively skewed) B Skewed to the right (positively skewed) C Bimodal D Uniform E Approximately normal

B Skewed to the right (positively skewed)

Nutritionists examined the sodium content of different brands of potato chips. Each brand was classified as either healthy or regular based on how the chips were marketed to the public. The sodium contents, in milligrams (mg) per serving, of the chips are summarized in the boxplots below. Based on the boxplots, which statement gives a correct comparison between the two classifications of the sodium content of the chips? A The number of brands classified as healthy is greater than the number of brands classified as regular. B The interquartile range (IQR) of the brands classified as healthy is greater than the IQR of the brands classified as regular. C The range of the brands classified as healthy is less than the range of the brands classified as regular. D The median of the brands classified as healthy is more than twice the median of the brands classified as regular. E The brand with the least sodium content and the brand with the greatest sodium content are both classified as healthy.

B The interquartile range (IQR) of the brands classified as healthy is greater than the IQR of the brands classified as regular.

One way to measure the duration of subterranean disturbances such as earthquakes and mining is to calculate the root-mean-square time. The following histograms summarize the distributions of the root-mean-square times for two sources of disturbances. Based on the histograms, which of the following correctly compares the two distributions? A The median of the earthquake disturbances is equal to the median of the mining disturbances. B The median of the earthquake disturbances is less than the median of the mining disturbances. C The range of the earthquake disturbances is equal to the range of the mining disturbances. D The range of the earthquake disturbances is less than the range of the mining disturbances. E The mode of the earthquake disturbances is equal to the mode of the mining disturbances.

B The median of the earthquake disturbances is less than the median of the mining disturbances.

The following relative frequency table shows the political party affiliation for a sample of 500 people in a certain town. Which of the following statements is supported by the table? A The number of people affiliated with the Republicans is 30. B The number of people affiliated with the Independents is 100. C Less than half of the people are affiliated with the Democrats or the Republicans. D At least 200 people are affiliated with the Democrats. E At least 80 people are affiliated with the Green Party or the Libertarians.

B The number of people affiliated with the Independents is 100.

The following table shows summary statistics for the number of hours a group of students spent playing video games last Monday and last Saturday. Based on the summary statistics, which of the following gives the best comparison of the range and the interquartile range (IQR) of the two days? A The range and IQR of hours played on Monday are both greater than the range and IQR of hours played on Saturday. B The range and IQR of hours played on Monday are both less than the range and IQR of hours played on Saturday. C The range and IQR of hours played on Monday are both equal to the range and IQR of hours played on Saturday. D The range of hours played on Monday is greater than the range of hours played on Saturday, and the IQR of hours played on Monday is less than the IQR of hours played on Saturday. E The range of hours played on Monday is less than the range of hours played on Saturday, and the IQR of hours played on Monday is greater than the IQR of hours played on Saturday.

B The range and IQR of hours played on Monday are both less than the range and IQR of hours played on Saturday.

Researchers conducted a telephone survey of 427 adults living in a large city. The adults were asked whether they planned to purchase a smart watch in the next year. The table shows the responses categorized by the region of the city in which the residents live. Which of the following graphical displays is most appropriate for comparing the proportions of those surveyed who plan to purchase a smart watch within the four regions? A A scatterplot B A boxplot C A segmented bar chart D A back-to-back stemplot E A dotplot

C A segmented bar chart

The pulse rate for each person in a sample of 20 men and 20 women was recorded. The boxplots below summarize the pulse rates for the men and the women in the sample. Which of the following statements about the people in the sample must be true? A There are more people between the first and third quartiles for women than there are between the first and third quartiles for men. B The person with the lowest pulse rate is a woman. C At least half of the women had higher pulse rates than three-fourths of the men. D More than half of the men had lower pulse rates than three-fourths of the women. E If a man and a woman were randomly selected from the 40 people, the man would have the lower pulse rate.

C At least half of the women had higher pulse rates than three-fourths of the men.

Administrators at a state university computed the mean GPA (grade point average) for juniors and seniors majoring in either physics or chemistry. The results are displayed in the table below. When juniors and seniors are grouped together, could physics majors have a higher mean GPA than chemistry majors? A No. The physics majors' mean GPA for juniors and seniors must be 3.0, while the chemistry majors' mean GPA for juniors and seniors must be 3.3. B No. There is not enough information to determine the mean GPA for each major, but it must be higher for chemistry majors than for physics majors. C Yes. It could happen. Whether it does happen depends on the number of juniors and seniors in each major. D Yes. It could happen. Whether it does happen depends on the variability of the GPAs within each of the four groups of students. E Yes. It could happen. Whether it does happen depends on the shapes of the distributions of the GPAs for each of the four groups of students.

C Yes. It could happen. Whether it does happen depends on the number of juniors and seniors in each major.

The director of a technical school was curious about whether there is a relationship between students who complete one of the school's most popular health sciences certificate programs and whether those students go on to complete more advanced studies in the health sciences within two years of completing the certificate program. She randomly selected 100 students who completed the program. Data collected on these students are shown in the table below. Which of the following statements is true for these 100 students? A Being a person who completed more advanced studies is more likely than being a person who did not complete more advanced studies. B Being a person who completed the program is less likely than being a person who did not complete the program. C Being a person who completed the program and completed more advanced studies is less likely than being a person who did not complete the program and did not complete more advanced studies. D Being a person who did not complete the program but completed more advanced studies is less likely than being a person who completed the program and completed more advanced studies. E Being a person who completed the program but did not complete more advanced studies is more likely than being a person who did not complete the program and did not complete more advanced studies.

D Being a person who did not complete the program but completed more advanced studies is less likely than being a person who completed the program and completed more advanced studies.

As part of a community service program, students in three middle school grades (grade 6, grade 7, grade 8) each chose to participate in one of three school-sponsored volunteer activities. The graph below shows the distribution for each class for the three activities. Based on the graph, which statement must be true? A Of all the students who chose activity B, the greatest number of students were in grade 6. B Grade 7 and grade 8 had the same number of students who did not choose activity A. C The grade with the greatest percentage of students who chose activity C was grade 8. D For students in grade 7, the number who chose activity C was greater than the number who chose activity B. E For students in grade 8, the number who chose activity A was greater than the number who chose activity B.

D For students in grade 7, the number who chose activity C was greater than the number who chose activity B.

The figure above summarizes the heights, in centimeters, of approximately 400 pine seedlings six years after they were planted at a center for environmental study. Approximately half of the trees were fertilized yearly, and the remaining trees were never fertilized. Which of the following statements about the medians and interquartile ranges (IQRs) of the heights of the two groups of trees 6 years after being planted is true? A The medians and IQRs are the same for the unfertilized trees and the fertilized trees. B The median for the unfertilized trees is greater than the median for the fertilized trees, and the IQR is also greater for the unfertilized trees. C The median for the unfertilized trees is the same as the median for the fertilized trees, and the IQR is greater for the unfertilized trees. D The median for the unfertilized trees is less than the median for the fertilized trees, and the IQR is greater for the unfertilized trees. E The median for the unfertilized trees is less than the median for the fertilized trees, and the IQR is less for the unfertilized trees.

D The median for the unfertilized trees is less than the median for the fertilized trees, and the IQR is greater for the unfertilized trees.

The following bar chart displays the relative frequency of responses of students, by grade level, when asked, "Do you volunteer in a community-service activity?" Which of the following statements is not supported by the bar chart? A More than 60% of both tenth-grade and eleventh-grade students responded yes. B Twelfth-grade students had the least percentage of students respond yes. C Less than 40% of tenth-grade students responded no. D The number of tenth-grade students who responded yes was greater than the number of ninth-grade students who responded yes. E The percentage of eleventh-grade students who responded no was less than the percentage of ninth-grade students who responded no.

D The number of tenth-grade students who responded yes was greater than the number of ninth-grade students who responded yes.

Grain moisture is a characteristic of grain that affects the price paid for the grain. A random sample of 28 loads of corn was evaluated for moisture as a percent of the total weight. A different random sample of 28 loads of soybeans was also evaluated for moisture. The data are displayed in the dotplots below. Based on the dotplots, which of the following is greater for the percent moisture of corn than for the percent moisture of soybeans? A The first quartile B The median C The third quartile D The range E The interquartile range

D The range

The following histogram summarizes the amount spent on plane tickets to travel home, in dollars, for a group of 30 college students. If the interval size is decreased from $200 to $100, which of the following must remain the same on the new histogram? A The heights of the bars B The widths of the bars C The number of bars D The sum of the frequencies E The shape of the distributio

D The sum of the frequencies

A survey of 57 students was conducted to determine whether or not they held jobs outside of school. The two-way table above shows the number of students by employment status (job, no job), and class (juniors, seniors). Which of the following best describes the relationship between employment status and class? A There appears to be no association, since the same number of juniors and seniors have jobs. B There appears to be no association, since close to half of the students have jobs. C There appears to be an association, since there are more seniors than juniors in the survey. D There appears to be an association, since the proportion of juniors having jobs is much larger than the proportion of seniors having jobs. E A measure of association cannot be determined from these data.

D. There appears to be an association, since the proportion of juniors having jobs is much larger than the proportion of seniors having jobs.

Janelle collected data on the amount of time in minutes each person in a large sample of customers spent in a local store. The data also included recording the gender of each customer. These data were used to generate the boxplots shown below. Which of the following statements is true? A The range in the amount of time in minutes males in the sample of customers spent in the store is approximately 40 minutes. B The mean amount of time in minutes males in the sample of customers spent in the store is approximately 20 minutes. C The third quartile of the amount of time in minutes males in the sample of customers spent in the store is approximately 45 minutes. D The interquartile range of the amount of time in minutes females in the sample of customers spent in the store is 15 minutes. E Approximately half of the males in the sample of customers spent at least as much time in the store as any female in the sample of customers.

E Approximately half of the males in the sample of customers spent at least as much time in the store as any female in the sample of customers.

A penalty kick in soccer involves two players from different teams, the shooter and the goalie. During the penalty kick the shooter will try to score a goal by kicking a soccer ball to the left or right of the goal area. To prevent the shooter from scoring a goal, the goalie will move to the left or right of the goal area. The following table summarizes the directions taken by the shooter and the goalie for 372 penalty kicks. Which of the following indicates an association between the shooter's choice of direction and the goalie's choice of direction? A The marginal relative frequencies for the shooter and the goalie are equal. B The marginal relative frequencies for the shooter and the goalie are not equal. C The row totals are not equal. D For the goalie, the relative frequency of a direction is equal to the relative frequency conditioned on the shooter's direction. E For the goalie, the relative frequency of a direction is not equal to the relative frequency conditioned on the shooter's direction.

E For the goalie, the relative frequency of a direction is not equal to the relative frequency conditioned on the shooter's direction.

College researchers wanted to know under what conditions people are more likely to complete and return a survey. As part of a study, the researchers prepared three sets of identical surveys and used three methods of delivering and returning the surveys. The methods are described as follows. In Class: The surveys were given to students in a class, and students were asked to return completed surveys to their instructor. Psychology: The surveys were given to students participating in a psychology experiment, and students were asked to return completed surveys to a collection box in the hallway of the psychology building. Dining Hall: The surveys were given to students in the dining hall, and students were asked to return completed surveys to a collection box outside the dining hall. The graph shows the percent of surveys returned and not returned for each delivery method. Which statement about delivery method and rate of survey return is supported by the graph? A There is a positive association between delivery method and rate of return. B There is a negative association between delivery method and rate of return. C The number of surveys given using the Dining Hall delivery method was less than the number given using either of the other delivery methods. D The Psychology delivery method displays the most symmetric results; the other delivery methods display skewed results. E The In Class delivery method had the greatest rate of return, and the Dining Hall delivery method had the least rate of return.

E The In Class delivery method had the greatest rate of return, and the Dining Hall delivery method had the least rate of return.

An airline recorded the number of on-time arrivals for a sample of 100 flights each day. The boxplot below summarizes the recorded data for one year. Based on the boxplot, which of the following statements must be true? A The range of the number of on-time arrivals is greater than 90. B The interquartile range of the number of on-time arrivals is 22. C The number of days that had at least 80 on-time arrivals is greater than the number of days that had at most 76 on-time arrivals. D The number of days that had from 76 to 80 on-time arrivals is equal to the number of days that had at most 76 on-time arrivals. E The difference between the median and the lower quartile for the number of on-time arrivals is less than 2.

E The difference between the median and the lower quartile for the number of on-time arrivals is less than 2.

A scientist recorded the duration of the eruptions of the Old Faithful geyser in Yellowstone National Park that occurred during a one-month time period. The histogram below shows the distribution of the duration, in seconds, of the eruptions. Based on the histogram, which of the following is the best description of the distribution? A The distribution is uniform, is centered at about 200 seconds, and has a range of at most 250 seconds. B The distribution is skewed to the left, is centered at about 125 seconds, and has a range of at most 250 seconds. C The distribution is skewed to the right, is centered at about 260 seconds, and has a range of at most 250 seconds. D The distribution displays two clusters, has a range of at most 200 seconds, and includes outliers below 75 seconds and above 325 seconds. E The distribution displays two clusters, with one cluster centered at about 125 seconds and the other centered at about 260 seconds, and has a range of at most 250 seconds.

E The distribution displays two clusters, with one cluster centered at about 125 seconds and the other centered at about 260 seconds, and has a range of at most 250 seconds.

The number of siblings was recorded for each student of a group of 80 students. Some summary statistics and a histogram displaying the results are shown below. An outlier is often defined as a number that is more than 1.5 times the interquartile range below the first quartile or above the third quartile. Using the definition of an outlier and the given information, which of the following can be concluded? A The median is greater than the mean, and the distribution has no outliers. B The median is greater than the mean, and the distribution has only one outlier. C The median is greater than the mean, and the distribution has two outliers. D The median is less than the mean, and the distribution has only one outlier. E The median is less than the mean, and the distribution has two outliers.

E The median is less than the mean, and the distribution has two outliers.

Which of the following statements must be true about the data sets A and B displayed in the histograms above? A The mean of data set A is equal to the mean of data set B. B The median of data set A is equal to the median of data set B. C The range of data set A is equal to the range of data set B. D The standard deviation of data set A is less than the standard deviation of data set B. E The standard deviation of data set A is greater than the standard deviation of data set B.

E The standard deviation of data set A is greater than the standard deviation of data set B.

The following table shows data for the 8 longest roller coasters in the world as of 2015. Which of the following variables is categorical? A Length B Type C Speed D Height E Drop

B Type

The histogram shown summarizes the responses of 100 people when asked, "What was the price of the last meal you purchased?" Based on the histogram, which of the following could be the interquartile range of the prices? A $40 B $21 C $10 D $5 E $3

D $5

At a local ice-cream store, 210 people were surveyed on whether they preferred eating ice cream from a cone or a cup. Of the 210 people surveyed, 70 were adults and 140 were children. Of the responses, 150 indicated the cone as the preferred method of eating ice cream. For those surveyed, there was no association between age and preferred method of eating ice cream. Which of the following tables shows the distribution of responses? A B C D E

C

A car rental agency has two locations in a city. The boxplots below summarize the miles driven for one day of single-day car rentals at each location. Based on the boxplots, which statement provides the best comparison of the two locations? A The number of single-day rentals is greater for location A than for location B. B The number of single-day rentals is less for location A than for location B. C Compared with location A, the miles driven for location B display more variability, and the median is greater. D Compared with location A, the miles driven for location B display less variability, and the median is greater. E Compared with location A, the miles driven for location B display less variability, and the median is about the same.

C Compared with location A, the miles driven for location B display more variability, and the median is greater.

For a sample of 42 rabbits, the mean weight is 5 pounds and the standard deviation of weights is 3 pounds. Which of the following is most likely true about the weights for the rabbits in this sample? A The distribution of weights is approximately normal because the sample size is 42, and therefore the central limit theorem applies. B The distribution of weights is approximately normal because the standard deviation is less than the mean. C The distribution of weights is skewed to the right because the least possible weight is within 2 standard deviations of the mean. D The distribution of weights is skewed to the left because the least possible weight is within 2 standard deviations of the mean. E The distribution of weights has a median that is greater than the mean. Related Content & Skills

C The distribution of weights is skewed to the right because the least possible weight is within 2 standard deviations of the mean.

A sociologist collected data from a sample of people on their highest level of education and the number of times they visited any fast food restaurant during the previous week. The data are summarized in the boxplots. Based on the boxplots, which of the following statements must be true? A The number of people surveyed at the more than four-year college level is greater than the number of people surveyed at the high school level. B The proportion of people surveyed from the first quartile to the third quartile at the four-year college level is less than the respective proportion at the community college level. C The interquartile range (IQR) for the number of visits at the community college level. D The maximum number of visits at the community college level is greater than the maximum number of visits at the high school level. E The median number of visits at the four-year college level is greater than the median number of visits at the high school level.

C The interquartile range (IQR) for the number of visits at the community college level.

The following histogram shows the ages, in years, of the people who attended a documentary at a movie theater. Based on the histogram, which of the following statements best describes the relationship between the mean and the median of the distribution of ages? A The mean and the median are equal in value because the distribution is symmetric. B The mean is most likely less than the median because the distribution is skewed to the right. C The mean is most likely less than the median because the distribution is skewed to the left. D The mean is most likely greater than the median because the distribution is skewed to the right. E The mean is most likely greater than the median because the distribution is skewed to the left.

C The mean is most likely less than the median because the distribution is skewed to the left.

A market researcher asked a group of men and women to choose their favorite color design from a sample of advertisements. The results are shown in the following table. Which of the following statements is not supported by the table? More men than women chose the color design red with black. Answer A: More men than women chose the color design red with black. A More women than men chose the color design yellow with black. Answer B: More women than men chose the color design yellow with black. B For men, the number who chose a design with black was greater than the number who chose a design with blue. Answer C: For men, the number who chose a design with black was greater than the number who chose a design with blue. C The color design chosen by the most people was green with blue. Answer D: The color design chosen by the most people was green with blue. D The total number of men surveyed by the market researcher was equal to the total number of women surveyed by the market researcher.

C. For men, the number who chose a design with black was greater than the number who chose a design with blue.

The following question(s) refer to the following scenario and set of data. In the 1830s, land surveyors began to survey the land acquired in the Louisiana Purchase. Part of their task was to note the sizes of trees they encountered in their surveying. The table of data below is for bur oak trees measured during the survey. An outlier may be defined as a data point that is more than 1.5 times the interquartile range below the lower quartile or is more than 1.5 times the interquartile range above the upper quartile. According to this definition, what is the diameter, in inches, of the smallest tree that is an outlier? A 4 B 28 C 30 D 34 E 36

D 34

As part of a science experiment, a student recorded 10 measurements of the temperature of a liquid. One of the measurements was an outlier when compared with the other 9 measurements. Which of the following must be true about the 9 measurements, excluding the outlier, when compared with the 10 measurements? (Note: An outlier is any number that is greater than the upper quartile or less than the lower quartile by at least 1.5 times the interquartile range.) A The median of the 9 measurements is less than the median of the 10 measurements. B The median of the 9 measurements is greater than the median of the 10 measurements. C The maximum of the 9 measurements is less than the maximum of the 10 measurements. D The maximum of the 9 measurements is greater than the maximum of the 10 measurements. E The standard deviation of the 9 measurements is less than the standard deviation of the 10 measurements.

E The standard deviation of the 9 measurements is less than the standard deviation of the 10 measurements.

Data were collected on 100 United States coins minted in 2018. Which of the following represents a quantitative variable for the data collected? A The type of metal used in the coin B The value of the coin C The color of the coin D The person depicted on the face of the coin E The location where the coin was minted

B The value of the coin

A researcher is studying a group of field mice. The distribution of the weight of field mice is approximately normal with mean 25 grams and standard deviation 4 grams. Which of the following is closest to the proportion of field mice with a weight greater than 33 grams? A 0.023 B 0.046 C 0.954 D 0.977 E 1.000

A 0.023

CHAPTER 2

CHAPTER 2

A certain motel is roughly 20 miles from the entrance to Yosemite National Park. The motel manager wants to get a better estimate of the distance and asks five people to each measure the distance, to the nearest tenth of a mile, using the odometer in his or her car. The manager will use the median of the five measurements as the estimate of the distance. Which of the following statements is NOT a statistical justification for the manager's plan? A Odometer reading should be considered a variable when used to measure this distance. B The median of the five measurements is more likely to be close to the actual distance than is a single measurement. C The actual distance should be considered a variable, and taking five measurements allows the manager to estimate the variability in the actual distance. D If one or two odometers give inaccurate readings, the estimate still should be fairly close to the actual distance. E The manager can get some indication of how far off the estimate might be.

C The actual distance should be considered a variable, and taking five measurements allows the manager to estimate the variability in the actual distance.

A golfer recorded the following scores for each of four rounds of golf: 86, 81, 87, 82. The mean of the scores is 84. What is the sum of the squared deviations of the scores from the mean? A ∑(x−x¯)=(86−84)+(81−84)+(87−84)+(82−84) B ∑|x−x¯|=|86−84|+|81−84|+|87−84|+|82−84| C 2∑|x−x¯|=2[|86−84|+|81−84|+|87−84|+|82−84|] D ∑(x−x¯)2=(86−84)2+(81−84)2+(87−84)2+(82−84)2 E [∑|x−x¯|]2=[|86−84|+|81−84|+|87−84|+|82−84|]2

D ∑(x−x¯)2=(86−84)2+(81−84)2+(87−84)2+(82−84)2

The following table summarizes the number of pies sold at a booth one day at a local farmers market. Which of the following statements is supported by the table? A More cherry pies were sold than any other type of pie. B Twice as many apple pies as key lime pies were sold. C More than half the pies sold were apple. D Fewer than 50 pies were sold at the booth that day. E The combined percentage of key lime pies sold and pumpkin pies sold was less than 50%.

E The combined percentage of key lime pies sold and pumpkin pies sold was less than 50%.

The following table shows data that were collected from a random sample of people, who indicated their age and their favorite sporting event to watch on television. Based on the results above, what proportion of the randomly sampled people are over age 12 years? A 900/3,500 B 1,300/3,500 C 1,200/3,500 D 2,300/3,500 E 1,000/3,500

D 2,300/3,500

Which of the following questions about cars in a school parking lot will allow for the collection of a set of categorical data? A How many blue cars are in the lot? B What are the gas mileages, in miles per gallon, of the cars in the lot? C What are the weights, in pounds, of the cars in the lot? D What is the number of cars in the lot with out-of-state license plates? E What are the colors of the cars in the lot?

E What are the colors of the cars in the lot?

As part of a study on the relationship between the use of tanning booths and the occurrence of skin cancer, researchers reviewed the medical records of 1,436 people. The table below summarizes tanning booth use for people in the study who did and did not have skin cancer. Of the people in the study who had skin cancer, what fraction used a tanning booth? A 190/265 B 190/896 C 190/1,436 D 265/1, 436 E 896/1, 436

B 190/896

The following data were collected from a random sample of people, who identified their favorite type of juice. The results are shown in the following two-way table. What proportion of the children identified orange as their favorite type of juice? A 400/1,000 B 400/700 C 400/2,000 D 600/1,300 E 1,000/2,000

B 400/700

Which of the following statistics is defined as the 50th percentile? A The mean B The median C The mode D The interquartile range E The standard deviation

B The median

Which of the following describes a continuous variable? A The number of items sold at a craft booth for one day B The number of apps downloaded from a website one day C The diameters of the tree trunks at an evergreen farm D The number of baskets made by a basketball player E The shoe sizes of all shoes on sale at a department store

C The diameters of the tree trunks at an evergreen farm

Professor James gave the same test to his three sections of statistics students. On the 35-question test, the highest score was 32 and the lowest was 15. Based on the information displayed in the boxplots above, which of the following statements is true? A Section 1 has the smallest interquartile range. B The lowest score in section 2 is higher than the highest score in either of the other sections. C Section 2 has the smallest range of scores. D The top 25% of scores in section 2 are lower than the highest score in section 3. E At least 50% of the scores in section 3 are higher than all of the scores in section 1.

E At least 50% of the scores in section 3 are higher than all of the scores in section 1.

Data on homes recently sold in a certain town included the area of the home, reported in square feet. The table below shows summary statistics of the reported areas, in square feet. An auditor determined that an error was made in the reported areas and that all of the areas should have been 100 square feet greater than what was reported. The areas were corrected and new summary statistics were reported. What are the interquartile range (IQR) and the standard deviation of the corrected areas? A IQR 102, standard deviation 61.0723 B IQR 102, standard deviation 161.0723 C IQR 202, standard deviation 61.0723 D IQR 202, standard deviation 161.0723 E IQR 187, standard deviation 61.0723

A IQR 102, standard deviation 61.0723

Some descriptive statistics for a set of test scores are shown above. For this test, a certain student has a standardized score of z = -1.2. What score did this student receive on the test? A 266.28 B 779.42 C 1008.02 D 1083.38 E 1311.98

B 779.42

Students in a large psychology class measured the time, in seconds, it took each of them to perform a certain task. The times were later converted to minutes. If a student had a standardized score of z = 1.72 before the conversion, what is the standardized score for the student after the conversion? A z = 0.26 B z = 1.03 C z = 1.72 D z = 1.98 E The standardized score for the student after the conversion cannot be determined.

C z = 1.72

Heights, in inches, for the 200 graduating seniors from Washington High School are summarized in the frequency table below. Which of the following statements about the median height is true? A It is greater than or equal to 78 inches. B It is greater than or equal to 72 inches but less than 78 inches. C It is greater than or equal to 66 inches but less than 72 inches. D It is greater than or equal to 60 inches but less than 66 inches. E It is less than 60 inches.

D It is greater than or equal to 60 inches but less than 66 inches.

Data will be collected on the following variables. Which variable can be considered discrete? A The height of a person B The weight of a person C The length of a person's arm span D The time it takes for a person to solve a puzzle E The number of books a person finished reading last month

E The number of books a person finished reading last month

Height, in meters, is measured for each person in a sample. After the data are collected, all the height measurements are converted from meters to centimeters by multiplying each measurement by 100. Which of the following statistics will remain the same for both units of measure? A The mean of the height measurements B The median of the height measurements C The standard deviation of the height measurements D The maximum of the height measurements E The z-scores of the height measurements

E The z-scores of the height measurements

The back-to-back stem-and-leaf plot below gives the percentage of students who dropped out of school at each of the 49 high schools in a large metropolitan school district. Which of the following statements is NOT justified by these data? A The drop-out rate decreased in each of the 49 schools between the 1989-90 and 1992-1993 school years. B For the school years shown, most students in the 49 schools did not drop out of high school. C In general drop-out rates decreased between the 1989-90 and 1992-1993 school years. D The median drop-out rate of the 49 high schools decreased between the 1989-90 and 1992-1993 school years. E The spread between the schools with the lowest drop-out rates and those with the highest drop-out rates did not change much between the 1989-90 and 1992-1993 school years.

A The drop-out rate decreased in each of the 49 schools between the 1989-90 and 1992-1993 school years.

For the three histograms above, which of the following correctly orders the histograms from the one with the smallest proportion of data above its mean to the one with the largest proportion of data above its mean? A J, K, L B J, L, K C K, L, J D L, K, J E All three histograms

B J, L, K

Each person in a random sample of adults was asked how many DVDs he or she owned. Summary statistics are given below. Which of the following statements is true? A Seventy-five percent of the adults in the sample own more than 95 DVDs. B Fifty percent of the adults in the sample own between 0 and 129.4 DVDs. C The distribution of the number of DVDs owned appears to be approximately symmetric. D The interquartile range of the number of DVDs owned is 65. E The distribution of the number of DVDs owned contains outliers on both the low side and the high side.

D The interquartile range of the number of DVDs owned is 65.

The number of hurricanes reaching the East Coast of the United States was recorded for each of the last ten decades by the National Hurricane Center. Summary measures are shown below. Min = 12 Max = 24 Lower quartile = 15 Upper quartile = 18 Median = 16 n = 10 Which of the following statements is true? A The smallest observation is 12 and it is an outlier. No other observations in the data set could be outliers. B The largest observation is 24 and it is an outlier. No other observations in the data set could be outliers. C Both 12 and 24 are outliers. It is possible that there are also other outliers. D 12 is an outlier and it is possible that there are other outliers at the low end of the data set. There are no outliers at the high end of the data set. E 24 is an outlier and it is possible that there are other outliers at the high end of the data set. There are no outliers at the low end of the data set.

E 24 is an outlier and it is possible that there are other outliers at the high end of the data set. There are no outliers at the low end of the data set.

An amusement park attraction has a sign that indicates that a person must be at least 48 inches tall to ride the attraction. The following boxplot shows the heights of a sample of people who entered the amusement park on one day. Based on the boxplot, approximately what percent of the people who entered the amusement park met the height requirement for the attraction? A 25% B 48% C 50% D 75% E 100%

C 50%

A marketing firm obtained random samples of 20 people in five regions of the country to investigate the level of interest in a new product. People in the sample were asked to rate their level of interest on a scale from 1 to 10, with 1 being the least amount of interest and 10 being the greatest. The histograms show the results for each region. The graph for which region displays data for level of interest with the least standard deviation? A B C D E

D

For which of the following distributions is the mean greater than the median? A B C D E

A

At a small coffee shop, the distribution of the number of seconds it takes for a cashier to process an order is approximately normal with mean 276 seconds and standard deviation 38 seconds. Which of the following is closest to the proportion of orders that are processed in less than 240 seconds? A 0.17 B 0.25 C 0.36 D 0.83 E 0.95

A 0.17

he prices, in thousands of dollars, of 304 homes recently sold in a city are summarized in the histogram below. Based on the histogram, which of the following statements must be true? A The minimum price is $250,000. B The maximum price is $2,500,000. C The median price is not greater than $750,000. D The mean price is between $500,000 and $750,000. E The upper quartile of the prices is greater than $1,500,000.

C The median price is not greater than $750,000.

In a certain school district, students from grade 6 through grade 12 can participate in a school-sponsored community service activity. The following bar chart shows the relative frequencies of students from each grade who participate in the community service activity. Which of the following statements is supported by the bar chart? A The greatest number of participating students was in grade 9. B The number of participating students in grade 6 was equal to the number of participating students in grade 7. C The relative frequency of all participating students in grades 6 and 7 combined was 0.60. D Grade 12 had the least relative frequency of participating students. E Grade 11 had the greatest relative frequency of participating students.

D Grade 12 had the least relative frequency of participating students.

A local company is interested in supporting environmentally friendly initiatives such as carpooling among employees. The company surveyed all of the 200 employees at the downtown offices. Employees responded as to whether or not they own a car and to the location of the home where they live. The results are shown in the table below. Which of the following statements about a randomly chosen person from these 200 employees is true? A If the person owns a car, he or she is more likely to live elsewhere in the city than to live in the downtown area in the city. B If the person does not own a car, he or she is more likely to live outside the city than to live in the city (downtown area or elsewhere). C The person is more likely to own a car if he or she lives in the city (downtown area or elsewhere) than if he or she lives outside the city. D The person is more likely to live in the downtown area in the city than elsewhere in the city. E The person is more likely to own a car than not to own a car.

A If the person owns a car, he or she is more likely to live elsewhere in the city than to live in the downtown area in the city.

The distributions of four variables are shown in the following histograms. Which of the following shapes is NOT represented by one of the four distributions? A Uniform B Bimodal C Skewed to the left D Skewed to the right E Symmetric and unimodal

A Uniform

Three brands of candy pieces—X, Y, and Z—are made in many colors. Shaela bought one bag of each brand and counted the number of pieces of each color. The graph below shows the relative frequency distribution of colors for each bag. Which of the following statements must be true? A For Brand X, there were more green candy pieces than red candy pieces in the bag. B For Brand Y, there were more red candy pieces than green candy pieces in the bag. C There were more green candy pieces in the Brand X bag than were in the Brand Z bag. D There were the same number of blue candy pieces in the Brand X bag as were in the Brand Y bag. E The number of blue candy pieces in the Brand Z bag was equal to the sum of the number of blue candy pieces in the other two bags.

B For Brand Y, there were more red candy pieces than green candy pieces in the bag.

The following pie chart summarizes the results of a survey given to airlines about the primary reason for flight delays. Which of the following statements is supported by the pie chart? A The reason given most frequently was runway closure. B More delays were caused by weather than by all other reasons combined. C More delays were caused by runway closure than were caused by overbooking. D Overbooking and runway closure accounted for greater than one-fourth of the reasons given for flight delays. E The combined percentage for other and runway closure was equal to the percentage for overbooking.

B More delays were caused by weather than by all other reasons combined.

A study was conducted on three types of home siding and the type of damage done to the siding by woodpeckers. Each hole made by a woodpecker was classified as either drumming (territorial signaling), foresting (looking for food), or nesting. The following bar chart shows the relative frequency of the holes for each type of siding. Which of the following statements is supported by the bar chart? A The proportion of holes created for drumming is the same for all three siding types. B The proportion of holes created for drumming is greatest for grooved plywood. C The proportion of holes created for drumming is least for grooved plywood. D The number of holes created for drumming is least for grooved plywood. E The number of holes created for drumming is greatest for nonwood.

C The proportion of holes created for drumming is least for grooved plywood.

Research indicates that the standard deviation of typical human body temperature is 0.4 degree Celsius (C). Which of the following represents the standard deviation of typical human body temperature in degrees Fahrenheit (F), where F=9/5C+32 A 9/5(0.4)+32 B 9/5(0.4) C 9/5(0.4)2 D (9/5)2(0.4) E (9/5)2(0.4)2

B 9/5(0.4)

Gina's doctor told her that the standardized score (z- score) for her systolic blood pressure, as compared to the blood pressure of other women her age, is 1.50. Which of the following is the best interpretation of this standardized score? A Gina's systolic blood pressure is 150. B Gina's systolic blood pressure is 1.50 standard deviations above the average systolic blood pressure of women her age. C Gina's systolic blood pressure is 1.50 above the average systolic blood pressure of women her age. D Gina's systolic blood pressure is 1.50 times the average systolic blood pressure for women her age. E Only 1.5% of women Gina's age have a higher systolic blood pressure than she does.

B Gina's systolic blood pressure is 1.50 standard deviations above the average systolic blood pressure of women her age.

A split ticket is a voting pattern in which a voter casts votes for candidates from more than one political party. In a recent study, 1,000 men and women were asked whether they voted a split ticket in the last election. The totals are shown in the following table. What value of a would indicate no association between gender and voting pattern for the people in the sample? A 300 B 400 C 480 D 500 E 800

C 480

At a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 75 and a standard deviation of 12. The scores on the calculus final are also approximately normally distributed, with a mean of 80 and a standard deviation of 8. A student scored 81 on the chemistry final and 84 on the calculus final. Relative to the students in each respective class, in which subject did this student do better? A The student did better in chemistry. B The student did better in calculus. C The student did equally well in each course. D There is no basis for comparison, since the subjects are different from each other and are in different departments. E There is not enough information for comparison, because the number of students in each class is not known.

C The student did equally well in each course.

The height of 3-year-old boys is approximately normally distributed. Duncan and Shane are 3-year-old boys.Duncan is 32.0 inches tall and is at the 32nd percentile of the distribution. Shane is 34.0 inches tall and is at the 62nd percentile of the distribution. Which of the following is closest to the mean of the height distribution? A 32.50 inches B 32.79 inches C 33.00 inches D 33.21 inches E 36.53 inches

D 33.21 inches

A sample of 942 homeowners are classified, in the two-way frequency table below, by the number of credit cards they have and the number of years they have owned their current homes. Of the homeowners in the sample who have four or more credit cards, what proportion have owned their current homes for at least one year? A 78/212 B 78/258 C 78/942 D 212/942 E 258/942

A 78/212

The following segmented bar chart shows the number of flights that were either on time or delayed at three different airports on one day. Which of the following statements is supported by the bar chart? Airport T has the greatest percentage of on-time flights compared to the other two airports. Answer A: Airport T has the greatest percentage of on-time flights compared to the other two airports. A Airport R has the least percentage of on-time flights compared to the other two airports. Answer B: Airport R has the least percentage of on-time flights compared to the other two airports. B The number of on-time flights at Airport S is half the number of on-time flights at Airport T. Answer C: The number of on-time flights at Airport S is half the number of on-time flights at Airport T. C The number of on-time flights at Airport R is less than the number of on-time flights at Airport S. Answer D: The number of on-time flights at Airport R is less than the number of on-time flights at Airport S. D The number of flights at Airport T is equal to the total number of flights at Airports R and S combined.

C. The number of on-time flights at Airport S is half the number of on-time flights at Airport T.

The distribution of monthly rent for one-bedroom apartments in a city is approximately normal with mean $936 and standard deviation $61. A graduate student is looking for a one-bedroom apartment and wants to pay no more than $800 in monthly rent. Of the following, which is the best estimate of the percent of one-bedroom apartments in the city with a monthly rent of at most $800 ? A 1.3% B 2.5% C 50% D 95% E 97.5%

A 1.3%

The distribution of heights of 6-year-old girls is approximately normally distributed with a mean of 46.0 inches and a standard deviation of 2.7 inches. Aliyaah is 6 years old, and her height is 0.96 standard deviation above the mean. Her friend Jayne is also 6 years old and is at the 93rd percentile of the height distribution. At what percentile is Aliyaah's height, and how does her height compare to Jayne's height? A Aliyaah's height is at the 17th percentile of the distribution, and she is shorter than Jayne. B Aliyaah's height is at the 67th percentile of the distribution, and she is shorter than Jayne. C Aliyaah's height is at the 67th percentile of the distribution, and she is taller than Jayne. D Aliyaah's height is at the 83rd percentile of the distribution, and she is shorter than Jayne. E Aliyaah's height is at the 83rd percentile of the distribution, and she is taller than Jayne.

D Aliyaah's height is at the 83rd percentile of the distribution, and she is shorter than Jayne.

The following list shows the selling prices of 8 houses in a certain town. What is the median selling price of the houses in the list? A $263,200 B $283,300 C $288,450 D $290,600 E $293,400

B $283,300

The dotplot below displays the total number of miles that the 28 residents of one street in a certain community traveled to work in one five-day workweek. Which of the following is closest to the percentile rank of a resident from this street who traveled 85 miles to work that week? A 60 B 70 C 75 D 80 E 85

B 70

The following bar chart shows the relative frequency of days of rain for 30 days in four regions of a certain state. Which of the following statements is not supported by the bar chart? A Region D had the greatest percentage of days of rain. B Region B had the least percentage of days of rain. C Region A had more than 15 days of rain. D Region C had more than 25 days of rain. E Region D had less than 23 days of rain.

D Region C had more than 25 days of rain.

A graph (not shown) of the selling prices of homes in a certain city for the month of April reveals that the distribution is skewed to the left. Which of the following statements is the most reasonable conclusion about the selling prices based on the graph? A The mean is greater than the median. B The median is the average of the first quartile and the third quartile. C There are fewer selling prices between the first quartile and the median than there are between the median and the third quartile. D There are more selling prices that are less than the mean than selling prices that are greater than the mean. E The value of maximum minus third quartile is less than the value of first quartile minus minimum.

E The value of maximum minus third quartile is less than the value of first quartile minus minimum.

The following dotplot shows the scores of 25 people who played an online trivia game. Which of the following statements is the best description of the distribution of scores? A The distribution is roughly symmetric. B The distribution is roughly uniform. C The distribution is skewed left. D The distribution is skewed right. E The distribution is bimodal.

D The distribution is skewed right.

A certain type of remote-control car has a fully charged battery at the time of purchase. The distribution of running times of cars of this type, before they require recharging of the battery for the first time after its period of initial use, is approximately normal with a mean of 80 minutes and a standard deviation of 2.5 minutes. The shaded area in the figure below represents which of the following probabilities? A The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 75 minutes and 82.5 minutes. B The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 75 minutes and 85 minutes. C The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 77.5 minutes and 82.5 minutes. D The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 77.5 minutes and 85 minutes. E The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 77.5 minutes and 87.5 minutes.

A The probability that the running time of a randomly selected car of this type, before it requires recharging of the battery for the first time after its period of initial use, is between 75 minutes and 82.5 minutes.

Shalise competed in a jigsaw puzzle competition where participants are timed on how long they take to complete puzzles of various sizes. Shalise completed a small puzzle in 75 minutes and a large jigsaw puzzle in 140 minutes. For all participants, the distribution of completion time for the small puzzle was approximately normal with mean 60 minutes and standard deviation 15 minutes. The distribution of completion time for the large puzzle was approximately normal with mean 180 minutes and standard deviation 40 minutes. Approximately what percent of the participants had finishing times greater than Shalise's for each puzzle? A 16% on the small puzzle and 16% on the large puzzle B 16% on the small puzzle and 84% on the large puzzle C 32% on the small puzzle and 68% on the large puzzle D 84% on the small puzzle and 84% on the large puzzle E 84% on the small puzzle and 16% on the large puzzle

B 16% on the small puzzle and 84% on the large puzzle

For a recent season in college football, the total number of rushing yards for that season is recorded for each running back. The mean number of rushing yards for the running backs that season is 790 yards. One running back had 1,637 rushing yards for the season, which is 2.42 standard deviations above the mean number of rushing yards. What is the standard deviation of the number of rushing yards for the running backs that season? A 250 yards B 300 yards C 350 yards D 400 yards E 450 yards

C 350 yards